"All wargamers are Republicans," said William, smiling, as he studied the board where the five ships of his Union squadron faced four oncoming Confederate vessels.

A couple of the youngish men clustered around the table rolled their eyes, but most of the players paid no attention. "William ran for Congress once," one of them explained.

William regarded the impertinent fellow briefly through his heavy glasses. "The reason all wargamers -- or anyway all good wargamers are Republicans," he went on, "is that you have to have a certain amount of military and historical knowledge, which is anathema to a liberal democracy."

William seemed more than willing to expand on this theme, but just then an enemy salvo began to descend upon USS Galena, second ship in the Federal battle line. "Not to worry," he said to the newcomer who was serving as her captain. "At this range he's wasting his time."

The Rebel captain rolled his dice, which came up 2 and 6. "Hit!" came the chorus. He rolled again, 3 and 5. "Aft, portside, hull," announced the player in charge of the combat-results chart.

The next roll came up snake eyes, and the Rebel captain grinned as William groaned.

"Penetration, magazine, critical hit," was the pronouncement. "Loss of three armor factors, two crew, and your speed's down to 5 knots. You've got a Level III fire; that cuts your crew to 31 and you need 11 men to man your guns, wheel and engine, so you've got 20 free to fight the fire, and one turn to get it under control or you'll blow up. Welcome to the wild, wild world of wargames."

Actually it's a mild, mild world, judging from the easy camaraderie found in such area game centers as The Little Soldier in Alexandria, where this session of "Ironclads" was unfolding on a Thursday evening. Newcomers were quickly on a first-name basis,and there was never a cussword to be heard, even from players who should have been winning but because of bad bounces were going down in flames.

With the possible exception of Moscow, Washington is the wargaming center of the world. At the Pentagon they play for keeps: Facility at thinking about the unthinkable may have a profound effect on one's advance along the command-and-general-staff track.

Until he joined the game, the newcomer had prided himself on his knowledge of the Civil War, but he began to feel meek indeed when youngsters barely free of zits chattered glibly about the ships represented by the cardboard markers. "She's got 14 inches of armor over her entire upperworks," somebody said of a Confederate vessel.

"And she's a deathtrap," scorned another. "Rap her with anything, even a 32-pounder Dahlgren, and the inner face of the armor spalls off into her interior spaces. Only thing to do with the beast is scuttle her in a harbor entrance."

Dice or computer-generated random numbers are central to all wargames, because there has to be some way to resolve a combat situation, and anyway the warrior's fate has always been as much a matter of luck as of pluck.

The other players agreed it was deuced unfair that Galena, which could outrun or outgun any vessel in the Southern fleet, was forced to retire and lick her wounds because of one extremely unlikely Rebel hit, especially since her captain had provided the refreshments. "Fortunes of war, you know," said one, with a Gallic shrug.

William sorely felt the loss, because he had been counting on the stricken ship's 150-pounder bow and stern guns. "We've superior range and weight of metal," he had said at the pregame captains' conference. "We'll smother the scoundrels in a welter of spray." He decided to press the attack anyway, ordering his captains to close and ram the Rebels as poor Galena, now hull-down on the horizon behind him, exploded and sank with all hands save her captain, whom William omnipotently transferred to command of USS Monongahela.

"There probably are about a million people in this country who play these games," said Little Soldier owner Dennis Largess, who could be described as jolly if he were less laid-back. "They break down into three basic types.

"Your main group, fully half of them, are history buffs seeking better understanding of various battles or campaigns, or who are tired of just reading about it. It's a way of going over the ground without getting your feet muddy.

"Then there are those, about one in three, whose main interest is the competition. They want to master the game.

"A smaller fraction is people who like role-playing and a sense of power; their aim is to master the other players."

All three types were present at this "Ironclads" game, with William representing the remaining, indescribable fraction. He turned aside inquiries about his real life, but tried very patiently to explain another of the many wargames he's involved in, called "Imperialism III HELLAS," which has a score of players from Canada to California and has been running since 1981 with no end in sight.

"This game covers the wars of the Spartan hegemony in late classical Hellas 404-360 B.C.," begins the instruction sheet for Imperialism III. "The two players with the most victory points are co-winners -- all others are losers." Each player represents a city-state, and each move represents the passage of a year. Alliances are necessary, as are lying, backstabbing and the breaking of solemn vows.

A player in another game William's currently managing took him aside during a lull in the "Ironclads" action. "Are you in favor of peace in Europe?" he asked.

"I'm in favor of peace among Christians until the Dark Empire is put paid," William replied. "Make of that what you will."

In the silence that ensued came a snatch of conversation from another table in the cluttered loft, where a session of the World War I game "Wings" was under way:

"I'm going after him."

"But he's on fire -- he's going down already."

"I don't care, I'm gonna kill him."

"Well, yes, he might walk away from the wreck, and then he'd get experience points . . ."

This sort of talk is all sound and fury, signifying nothing, Largess said. "A lot of people, especially women, think wargamers are warlovers, and it turns them off. The fact is, most of us have gone deeply enough into history to understand how terrible war is. But a game on the deliberations of the Continental Congress wouldn't be much fun; you have to go to the conflict situations."

There are hundreds if not thousands of wargames covering virtually every major battle and campaign in history, including half a dozen on Gettysburg alone. Sooner or later nearly all will be played out at The Little Soldier, or at the Washington Gamers Association (which in spite of the name meets in Northern Virginia and is the oldest established permanent floating wargame in these parts) or at Fantastic Gamers, headquartered at the Dream Wizards shop in Rockville. Newcomers are always welcome.

But in the "Ironclads" game things went from bad to worse. Scarcely had the newcomer taken command of Monongahela when she took a hit in her engine room, and soon she was a blazing wreck trying to limp away in reverse as Rebel gunners pounded her gleefully.

"She's headed for the bottom," shopowner Largess said, "and anyway you're going to have to abandon ship if you want a ride to the subway." The dozen players still in the room hardly looked up as the proprietor left.

"I can't help noticing," the newcomer said tentatively, "that you just walked away and left a bunch of people in your store."

"Sure," Largess said. "They're good people, they'll take care of everything and lock up. If I couldn't do business with people like that, I wouldn't care to be in business." WHERE TO STUDY WAR SOME MORE Area shops that not only sell war games but also sponsor regular public playing sessions:

THE COMPLEAT STRATEGIST -- 103 East Broad Street, Fealls Church. 532-2477. Washington Gamers Association meets first and third Saturdays of each month.

DREAM WIZARDS -- 84 Halpine Court, Rockville. 881-3530. Headquarters of Fantastic Gamers, who meet Thursday evenings "from 8 to whenever" and Sundays "from noon to whenever."

THE LITTLE SOLDIER -- 100 South Patrick Street, Alexandria. 548-7357. Gamers gather from 5 onwards on Thursdays, 1 to 6 Sundays.